峰值法和数据包络分析法在中国远洋鱿钓渔业方面的应用与比较分析

概述了PTP和DEA法的基本理论，并将其应用于我国的远洋鱿钓渔业，结果表明，1999年我国北太平洋鱿钓渔业的“捕捞能力”尚未得到充分的发挥，仍有潜力可挖；影响西南大西洋鱿钓渔业“捕捞能力”的主要因素是制冷能力，钓机数，集鱼灯和水下灯，而船长，船舶总吨位，功率和舱容仅为次要因素。通过应用，本文分析比较了这两种方法的特点；PTP法长于在时间序列方面的一个纵向的分析，能够在一定程度上反映渔业技术和资源随时间的变化而发生的变化，而DEA法则擅于在捕捞单位间进行横向的“能力”比较，并能对影响“捕捞能力”的因素进行有效的灵敏度分析。     

New Hippolide Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activity from the Marine Sponge Hippospongia lachne

Five new sesterterpenoids, compounds 1–5, have been isolated from the sponge Hippospongia lachne off Yongxing Island in the South China Sea. The structures of compounds 1–5 were elucidated through extensive spectroscopic analysis, including HRMS, 1D, and 2D NMR experiments. The stereochemistry, including absolute configurations of these compounds, was determined by spectroscopic, chemical, and computational methods. Compounds 1 and 5 showed moderate protein tyrosine phosphatase 1B (PTP1B) inhibitory activities with IC₅₀ values of 5.2 μM and 8.7 μM, respectively, more potent than previously reported hippolides.     

棉株果枝部位、温光复合因子及施氮量对纤维比强度形成的影响

 【目的】明确果枝部位、温光复合因子和施氮量对棉纤维比强度形成过程的定量关系及两者的补偿效应,探明棉纤维比强度形成的生态基础。【方法】以杂交棉（科棉1号）和常规棉（美棉33B）为材料,于2005年在江苏南京（118°50′E, 32°02′N,长江流域下游棉区）和江苏徐州（117°11′E, 34°15′N,黄河流域黄淮棉区）设置分期播种（4月25日、5月25日）和施氮量（0、240、480 kg N•hm-2）试验,研究棉株果枝部位、温光复合因子（用纤维加厚发育期的累积辐热积PTP表示）和施氮量对纤维比强度形成的影响。【结果】（1）棉株果枝部位显著影响纤维比强度的形成,并与温光复合因子存在协同效应。棉株中部果枝铃发育期温光条件适宜,其纤维比强度显著大于其它果枝部位铃;随温光条件变差,纤维比强度在果枝部位间的差异不明显。（2）棉纤维比强度随花后天数的增加可分为快速增加和稳定增加两个时期,PTP与纤维比强度快速增加期的日均增长速率（VRG）线性正相关、与快速增加持续期（TRG）线性负相关,与稳定增加期的日均增长速率（VSG）、持续期（TSG）及最终棉纤维比强度（Strobs）呈开口向下的抛物线关系。当PTP达到291 MJ•m-2左右时,纤维比强度Strobs最大（科棉1号、美棉33B分别为34.8、31.9 cN•tex-1）,品种间差异主要源于纤维比强度稳定增加期（中科棉1号和美棉33B的VSG、TSG分别为0.32 cN•tex-1•d-1、21 d和0.18 cN•tex-1•d-1、24 d）。（3）纤维比强度达到最大值所需的PTP随施氮量增加而减小,施氮量可通过棉铃对位叶叶氮浓度（NA）影响纤维比强度的形成,棉花氮素营养对温光复合因子存在补偿效应,当PTP高于104 MJ•m-2时,240 kg N•hm-2下的NA更适宜于比强度的形成;PTP低于此值时,增加施氮量可对温光复合因子进行补偿,以利于高强纤维形成。【结论】棉株果枝部位显著影响纤维比强度的形成,且与温光复合因子存在互作效应;温光复合因子、施氮量均显著影响棉纤维比强度的形成,且后者对前者存在补偿效应;棉纤维比强度形成过程可分为快速增加和稳定增加两个阶段,后者是品种间纤维比强度形成差异的主要阶段。     

Potential Bioactive Compounds from Seaweed for Diabetes Management

Diabetes mellitus is a group of metabolic disorders of the endocrine system characterised by hyperglycaemia. Type II diabetes mellitus (T2DM) constitutes the majority of diabetes cases around the world and are due to unhealthy diet, sedentary lifestyle, as well as rise of obesity in the population, which warrants the search for new preventive and treatment strategies. Improved comprehension of T2DM pathophysiology provided various new agents and approaches against T2DM including via nutritional and lifestyle interventions. Seaweeds are rich in dietary fibres, unsaturated fatty acids, and polyphenolic compounds. Many of these seaweed compositions have been reported to be beneficial to human health including in managing diabetes. In this review, we discussed the diversity of seaweed composition and bioactive compounds which are potentially useful in preventing or managing T2DM by targeting various pharmacologically relevant routes including inhibition of enzymes such as α-glucosidase, α-amylase, lipase, aldose reductase, protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl-peptidase-4 (DPP-4). Other mechanisms of action identified, such as anti-inflammatory, induction of hepatic antioxidant enzymes’ activities, stimulation of glucose transport and incretin hormones release, as well as β-cell cytoprotection, were also discussed by taking into consideration numerous in vitro, in vivo, and human studies involving seaweed and seaweed-derived agents.     

EGCG对线粒体PT孔开放及Ca~(2+)转运的影响

对线粒体膨胀及线粒体膜电位的研究发现,EGCG对Ca2+和H2O2导致的线粒体通透性改变有抑制其膨胀的作用。EGCG对Ca2+诱导的线粒体Ca2+释放随加入时间有抑制和加速释放的作用;与Ca2+同时加入,它们可以抑制线粒体对Ca2+的吸收和线粒体Ca2+的释放;在线粒体吸收Ca2+达到最大时加入EGCG,则促进线粒体Ca2+的释放,EGCG还可抑制Ca2+引起的线粒体膜电位的降低。     

PTP1B Inhibitory and Anti-Inflammatory Effects of Secondary Metabolites Isolated from the Marine-Derived Fungus Penicillium sp. JF-55

Protein tyrosine phosphatase 1B (PTP1B) plays a major role in the negative regulation of insulin signaling, and is thus considered as an attractive therapeutic target for the treatment of diabetes. Bioassay-guided investigation of the methylethylketone extract of marine-derived fungus Penicillium sp. JF-55 cultures afforded a new PTP1B inhibitory styrylpyrone-type metabolite named penstyrylpyrone (1), and two known metabolites, anhydrofulvic acid (2) and citromycetin (3). Compounds 1 and 2 inhibited PTP1B activity in a dose-dependent manner, and kinetic analyses of PTP1B inhibition suggested that these compounds inhibited PTP1B activity in a competitive manner. In an effort to gain more biological potential of the isolated compounds, the anti-inflammatory effects of compounds 1–3 were also evaluated. Among the tested compounds, only compound 1 inhibited the production of NO and PGE₂, due to the inhibition of the expression of iNOS and COX-2. Penstyrylpyrone (1) also reduced TNF-α and IL-1β production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of IκB-α, NF-κB nuclear translocation, and NF-κB DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of penstyrylpyrone (1) on the pro-inflammatory mediators and NF-κB DNA binding activity were associated with the HO-1 expression. Therefore, these results suggest that penstyrylpyrone (1) suppresses PTP1B activity, as well as the production of pro-inflammatory mediators via NF-κB pathway, through expression of anti-inflammatory HO-1.     

Marine Bromophenol Derivative 3,4-Dibromo-5-(2-bromo-3,4-dihydroxy-6-isopropoxymethyl benzyl)benzene-1,2-diol Protects Hepatocytes from Lipid-Induced Cell Damage and Insulin Resistance via PTP1B Inhibition

3,4-Dibromo-5-(2-bromo-3,4-dihydroxy-6-isopropoxymethyl benzyl)benzene-1,2-diol (HPN) is a bromophenol derivative from the marine red alga Rhodomela confervoides. We have previously found that HPN exerted an anti-hyperglycemic property in db/db mouse model. In the present study, we found that HPN could protect HepG2 cells against palmitate (PA)-induced cell death. Data also showed that HPN inhibited cell death mainly by blocking the cell apoptosis. Further studies demonstrated that HPN (especially at 1.0 μM) significantly restored insulin-stimulated tyrosine phosphorylation of IR and IRS1/2, and inhibited the PTP1B expression level in HepG2 cells. Furthermore, the expression of Akt was activated by HPN, and glucose uptake was significantly increased in PA-treated HepG2 cells. Our results suggest that HPN could protect hepatocytes from lipid-induced cell damage and insulin resistance via PTP1B inhibition. Thus, HPN can be considered to have potential for the development of anti-diabetic agent that could protect both hepatic cell mass and function.     

Isolation,Structural Characterization and Antidiabetic Activity of New Diketopiperazine Alkaloids from Mangrove Endophytic Fungus Aspergillus sp. 16-5c

Six new DIKETOPIPERAZINE alkaloids aspergiamides A–F (1–6), together with ten known alkaloids (7–16), were isolated from the mangrove endophytic fungus Aspergillus sp. 16-5c. The structures of the new compounds were elucidated based on 1D/2D NMR spectroscopic and HR-ESIMS data analyses. The absolute configurations of aspergiamides A-F were established based on the experimental and calculated ECD data. All the compounds were evaluated for the antidiabetic activity against α-glucosidase and PTP1B enzyme. The bioassay results disclosed compounds 1 and 9 exhibited significant α-glucosidase inhibitory with IC₅₀ values of 18.2 and 7.6 μM, respectively; compounds 3, 10, 11, and 15 exhibited moderate α-glucosidase inhibition with IC₅₀ values ranging from 40.7 to 83.9 μM; while no compounds showed obvious PTP1B enzyme inhibition activity.